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The Navy has issued an "Order to Account" for all Navy uniformed personnel, both active duty and selected Reserve, assigned to commands in the D.C. metro area in the wake of Monday's deadly Navy Yard Shooting.

According to the website, the NFAAS system allows the Navy to "account, assess, manage, and monitor the process for personnel and their families affected and/or scattered by a wide-spread catastrophic event."

Family members of Washington Navy Yard employees can also get information on their loved ones by calling a pair of hotlines. They can call the Warfighter and Family Support Center at 202-433-6151 or 202-433-9713.

The Navy has advised that employees trying to meet up with family members do so at Nationals Stadium. The D.C. Metro Police Department has designated Nationals Stadium's Parking Lot B at South Capitol & N St SE as the meeting spot.

At least 12 people were killed in Monday's shooting at the heavily secured Navy Yard, officials said. Suspected gunman Aaron Alexis, 34, of Fort Worth, Texas, is among the dead, several officials told NBC News. One other potential gunman may still be at large, officials said.

A "shelter in place" order is in effect for Navy Yard personnel as law enforcement agencies including the Naval Criminal Investigative Service, D.C. Metro Police, and the FBI investigate the mass shooting.

The Navy says 3,000 people work inside the southeast Washington facility, including command staff, headquarters directorates and field activities.

"Everyone here at the Department of Defense is saddened by the incident at the Washington Navy Yard this morning," Pentagon Press Secretary George Little said in a statement. "Our thoughts and prayers are with the victims. Secretary Hagel is closely following the situation and has assured the Navy we will provide any resource or capability needed to get the Washington Navy Yard community through this event."